#include <iostream>
#include <cstring>//前面带一个c代表c语言的库

namespace A
{
    void InsertTail()
    {
        std::cout<<"hello"<<std::endl;
    }
    int a = 3;
}

namespace B
{
    void InsertTail()
    {
        std::cout<<"wordl"<<std::endl;
    }
    int a = 5;
}

int main()
{
    //两句都一样
    using namespace A;
    A::InsertTail();

    return 0;
}